Medical Professional Corporation Tax Savings Calculator

Should a Doctor Incorporate in Ontario?

The honest answer starts with a correction, because the question is usually asked from the wrong premise.

Incorporating does not reduce the tax a physician pays on money they spend. Canada’s tax system is built on integration, which means the combined corporate and personal tax on a dollar that goes through a corporation and out as a dividend lands close to what the same dollar would have cost taken directly. Not identical, but close enough that nobody should incorporate expecting it.

What incorporation does is defer. Income left inside the corporation is taxed at 11.2 per cent in Ontario within the small business limit rather than at up to 53.53 per cent personally. The difference stays in the corporation and compounds until it is drawn, and the personal tax is paid then rather than now.

So the question is not how much you bill. It is how much you can leave behind. A physician billing six hundred thousand dollars who spends all of it gets very little from a corporation. A physician billing three hundred and fifty thousand who lives on one hundred and forty thousand gets a great deal.

That is why the calculator above asks for personal cash needs before it asks for anything else. Retained earnings are the whole engine.

The Arithmetic of the Deferral

Take a physician with four hundred and fifty thousand dollars of billings and one hundred and twenty thousand of overhead, so three hundred and thirty thousand of net practice income, who needs one hundred and fifty thousand after tax to live on.

Unincorporated, the full three hundred and thirty thousand is personal income, taxed at rates rising to 53.53 per cent. After tax there is roughly one hundred and seventy thousand left, and after living costs, around twenty thousand to invest.

Incorporated, the physician draws what they need and leaves the rest. The retained portion is taxed at 11.2 per cent rather than at the top personal rate, so a far larger amount survives into the investment account. On a balanced salary and dividend mix those are the default figures in the calculator above, and it returns roughly seventy-three thousand dollars retained and thirty-nine thousand of tax deferred in the year. Taking the whole draw as dividends rather than salary leaves more income in the corporation and increases both figures.

Over a twenty year career the compounding is where the real number appears. One year’s deferral at a five per cent return more than doubles over twenty years, and each subsequent year adds its own layer. This is not a tax trick. It is simply having more capital working for longer.

The tax is still owed. When the money eventually comes out as dividends, personal tax is paid then. What the physician has gained is two decades of returns on the government’s share.

Physician Incorporation Cost and CPSO Requirements in Ontario

A medicine professional corporation in Ontario is incorporated under the Business Corporations Act like any other company, and then it must obtain a certificate of authorization from the College of Physicians and Surgeons of Ontario before it can practise medicine. The certificate is not optional and it is not a formality.

The College’s rules shape the share structure in ways that matter a great deal for the tax planning.

All voting shares must be legally and beneficially owned by members of the profession. A physician’s spouse cannot hold voting shares in a medicine professional corporation unless they are themselves a physician. Non-voting shares may be held by the physician’s spouse, children, or a parent, and that is the opening through which family dividends are paid.

The corporation’s name must include the physician’s name as it appears on the College register and the words Medicine Professional Corporation. The corporation may only carry on the practice of medicine and activities ancillary to it, which rules out using the same company for unrelated business ventures.

Directors and officers must be shareholders, and the certificate is renewed annually with the College.

On cost, our fixed fee covers the incorporation, the NUANS search, the minute book, the share structure and the certificate of authorization application, and it includes HST. The College charges its own application and annual renewal fees directly. The ongoing accounting cost, which is the number that matters more, covers the T2, the financial statements, payroll for any salary and HST returns where the practice has taxable billings.

TOSI Rules and Physician Family Shareholders

This is the part of the answer that changed in 2018 and that a great many physicians have not fully absorbed.

Before then, paying dividends to a spouse or adult child through a professional corporation was straightforward and widely done. Section 120.4 now taxes split income received by a specified individual at the top marginal rate unless an exclusion applies, which removes the entire point of the payment.

Two exclusions matter, and one of them is closed to physicians.

The excluded business exclusion applies where the individual was actively engaged in the business on a regular, continuous and substantial basis, in the year or in any five prior years. Twenty hours a week is deemed to meet it. A spouse genuinely working in the practice, running the office, managing staff and billing, can fall within this, and it is the cleanest route available.

The excluded shares exclusion is the one most people reach for, requiring ten per cent of votes and value and a corporation earning under ninety per cent of its income from services. It is expressly unavailable where the corporation is a professional corporation. A medicine professional corporation cannot use it at all, and no share restructuring changes that.

There is a third route that arrives with time. Once the physician reaches sixty-five, amounts received by their spouse that would have been excluded had the physician received them are outside TOSI. That is a genuine planning point, and it is a reason to have the spouse holding non-voting shares well before that birthday rather than trying to arrange it afterwards.

The practical consequence is that dividends to a non-working spouse or to adult children in school are taxed at the top rate. Structures that assume otherwise were built for a regime that no longer exists.

Doctor Salary vs Dividend in Ontario

Once the corporation exists, the physician decides how to get paid, and there is no single right answer.

Salary is earned income. It creates RRSP contribution room at eighteen per cent of the prior year’s earned income up to the annual limit, it builds CPP entitlement, it is deductible to the corporation, and it requires a payroll account with source deductions remitted on time.

Dividends are paid from after-tax corporate income. They create no RRSP room, attract no CPP, need no payroll account, and can be declared when convenient rather than on a payroll cycle.

The considerations that usually decide it:

A physician who wants RRSP room needs salary, and for many that is decisive. The RRSP is the only meaningful tax-sheltered growth available outside the corporation, and dividends do not build it.

CPP is a genuine cost of salary at both the employee and employer rate, and whether it is worth having is a personal judgement about a government indexed pension against investing the same money yourself.

Where the corporation earns passive investment income, paying salary reduces corporate income and so can reduce the passive income problem described below.

And childcare expenses can only be deducted against earned income, which means a physician claiming them needs salary rather than dividends.

Most files land on a mix. Enough salary to fund RRSP room and cover the CPP decision deliberately, with the balance as dividends.

The Passive Income Grind

This is the rule that quietly erodes the benefit for physicians who have been incorporated for a while and have built up investments inside the corporation.

Where a corporation and its associated corporations earn more than fifty thousand dollars of adjusted aggregate investment income in a year, subsection 125(5.1) reduces the small business limit by five dollars for every dollar above that threshold. At one hundred and fifty thousand dollars of passive income the limit is gone entirely.

The effect is that active practice income that would have been taxed at 11.2 per cent is taxed at 26.5 per cent instead. The deferral narrows sharply.

It is not a reason to avoid investing in the corporation, but it is a reason to watch the threshold and to plan around it. Options include shifting some corporate investments towards growth rather than yield, using corporate-owned insurance in the right circumstances, paying more salary to reduce corporate income, and in larger structures moving investments into a holding company, though the associated corporation rules mean a holdco does not by itself solve the grind.

The threshold is not indexed, so it catches more physicians each year.

Medical Corporation and Holding Company in Ontario

A holding company sitting above the professional corporation comes up on most mature files, and the College’s rules constrain it.

A holding company cannot hold voting shares in a medicine professional corporation, because voting shares must be held by members of the profession personally. What a holdco can do in some structures is hold non-voting shares, subject to the College’s requirements being met, which is a point to confirm with the College and a lawyer rather than to assume.

Where it works, the purpose is to move surplus cash out of the practising corporation. That gets investments away from the professional liability exposure of the practice, and it separates the investment portfolio from the operating business.

What it does not do is solve the passive income grind, because the corporations are associated and the fifty thousand dollar threshold is tested across the group.

The other structure worth knowing about is the individual pension plan, which is a defined benefit pension registered for the physician and funded by the corporation. Contributions exceed RRSP limits at higher ages, the contributions are deductible to the corporation, and the plan assets are generally creditor protected. It suits a physician in their mid-forties or older with consistently high income and a long runway, and it brings actuarial and administrative costs that only make sense at scale.

Locum Physicians and the Personal Services Business Question

A locum incorporating needs one question answered that a physician with their own practice does not.

Where a locum works predominantly through a single hospital or clinic, on their schedule, using their facilities and their staff, the arrangement can look to the CRA like employment carried on through a corporation. That is a personal services business under subsection 125(7), and the consequences are severe: no small business deduction, no general rate reduction, a further five per cent federal tax producing a combined rate of 44.5 per cent, and paragraph 18(1)(p) denying almost every deduction except salary paid to the physician.

A locum working across several hospitals, setting their own availability, billing OHIP directly under their own billing number and carrying their own insurance is in a much stronger position. A locum effectively filling a staff role at one institution on a continuous basis is not.

This is worth resolving before incorporating rather than after, because a corporation that turns out to be a personal services business is worse than no corporation at all.

When Incorporation Is Not Worth It

We turn physicians away from incorporating regularly, and it is worth setting out when.

Where personal spending absorbs essentially all of the practice income, there is nothing to defer and the annual compliance cost is a straight loss. The rough threshold is retained earnings comfortably above the annual accounting cost, which in practice means leaving thirty to fifty thousand a year behind before the arithmetic clearly works.

Where the physician is in the first year or two of practice and paying down student debt, the money is better going to the debt than into a corporation.

Where income is irregular enough that some years are low, the benefit of smoothing exists but is smaller than it looks, because the personal rate in a low year is already modest.

Where a locum has an unresolved personal services business question, incorporating first and asking later is the wrong order.

And where the physician is within a few years of retirement with no accumulated corporate investments, the setup cost and the wind-up cost together can exceed the benefit of the remaining deferral.

What Happens to the Corporation at Retirement

Physicians think hard about incorporating and much less about unwinding, which is a mistake, because the exit shapes how the corporation should be run for the decade before it.

The common pattern is that the practice winds down while a substantial investment portfolio remains inside the corporation. That money has to come out, and it comes out as dividends taxed personally in the years it is drawn.

That is not a bad outcome. It is the deferral being repaid, and repaid in years when the physician has no practice income and is therefore in lower brackets than during their working life. A physician drawing one hundred thousand a year in dividends in retirement pays a materially lower average rate than the same dollars would have attracted at the top of their earning years. The bracket arbitrage is a second benefit sitting on top of the compounding.

Two mechanical points matter here. Corporate investment income attracts a high rate of tax when earned, part of which goes into the refundable dividend tax on hand account and is refunded to the corporation when taxable dividends are paid out. That refund is a real asset and it is one reason a corporation holding investments should not simply sit there undistributed indefinitely.

The other is the capital dividend account, which accumulates the non-taxable half of capital gains realised in the corporation and the proceeds of corporate-owned life insurance above the policy’s adjusted cost basis. Amounts in that account come out tax free by election. Keeping the account tracked properly, year by year, is a genuine piece of value, and it is commonly neglected until somebody needs to use it.

A physician who dies owning shares of a professional corporation creates a further set of problems, because the shares are deemed disposed of at fair market value and the corporation’s assets are then taxed again when distributed. Post-mortem planning exists to deal with that double taxation, and it is worth understanding before it is needed.

Practical Points We Raise With Every Physician

A few things come up on almost every file and are worth stating plainly.

The fiscal year end does not have to be 31 December, and for a practice a non-calendar year end can smooth the remuneration decision by giving you a window after the year’s billings are known. It is decided at incorporation and changing it later needs the CRA’s permission.

HST applies to some physician billings and not others. Insured services are exempt, but uninsured services, third party medical reports, some cosmetic procedures and teaching income can be taxable, and a practice crossing the thirty thousand dollar small supplier threshold on those has to register. Physicians are caught out by this more often than any other profession we act for.

A bonus accrued at the year end and paid within one hundred and eighty days is deductible in the year accrued, which gives room to decide the salary figure once the year’s numbers are actually known rather than guessing in advance.

Corporate-owned disability and critical illness insurance need care, because the tax treatment of premiums and benefits differs from personal ownership and the wrong structure can make a benefit taxable that would have been received tax free.

And the professional liability position is unchanged by incorporating. A medicine professional corporation does not shield the physician from liability for their own professional negligence, which is what the CMPA membership is for. The corporation limits commercial liabilities, not clinical ones.

How We Set a Physician File Up

We start with the billings, the overhead and the personal cash requirement, because those three numbers decide whether the conversation goes any further.

Where it does, the share structure comes next and it comes before the articles are filed. Voting shares to the physician, non-voting classes for family members the College permits, and a class structure that allows dividends to be declared separately on each. Getting that right at the start costs nothing and fixing it later costs a filing fee, legal work and sometimes a reorganisation.

Then the certificate of authorization application to the College, which has to be in place before the corporation practises.

Then the remuneration decision for the first year, salary against dividends, with the RRSP and CPP consequences set out rather than assumed.

And then the annual cycle: bookkeeping, the T2, payroll, and a review each year of whether the passive income threshold is approaching.

The fee is fixed and includes HST, set once we have seen the billings and the overhead. Payment is by Interac e-Transfer to info@gondaliyacpa.ca, with the security question set to Not Applicable because auto-deposit is enabled.

What This Calculator Does Not Cover

It models personal tax at the top marginal rate rather than through the full bracket structure, so figures at lower income levels understate the personal tax advantage of not incorporating. It is a comparison tool rather than a tax return.

It does not calculate your actual personal tax, the RRSP deduction, the dividend tax credit, or the refundable dividend tax on hand mechanism that applies to corporate investment income.

It does not price an individual pension plan, corporate-owned insurance, or the actuarial work either requires.

It does not address the College’s own fees or confirm that any particular share structure meets the College’s requirements, which is a question for the College and a lawyer.

And it does not settle whether a TOSI exclusion applies to a family member. That is a question of fact tested every year, and it should be examined on your own circumstances rather than assumed from a calculator.